SINGLE SUPPLY VOLTAGE TO FREQUENCY CONVERTER OPTIMIZED FOR LOW VOLTAGE SENSING ABOVE AND BELOW GROUND

摘要

A voltage to frequency converter using a charge pump to restore the output voltage of the input integrator. The charge pump implementation allows the voltage to frequency converter's input to sense voltage above and below ground with a single supply using a charge pump, which can provide either a positive charge or a negative charge as the restoring force to the integrator. Inclusion of an interleaved charge pump provides advantages of implementation simplicity and of high performance. The voltage to frequency converter concentrates all offset and leakage errors at the input of the integrator amplifier, which in the preferred embodiment is a chopper stabilized amplifier providing very low offset. The voltage to frequency converter is intended for realization in integrated circuit form, providing very high performance in an integrated circuit having very low power requirements.